The following applications of common assignee contain some common disclosure as the present application:
U.S. Patent Application entitled xe2x80x9cSystem and Method for Time Based Real-Time Reconfiguration of a Networkxe2x80x9d, filed Dec. 20, 1996, U.S. application Ser. No. 08/770,463, now U.S. Pat. No. 5,848,244.
1. Field of the Invention
The present invention relates generally to telecommunication network management systems. More specifically, the present invention is directed to high speed network reconfiguration.
2. Related Art
The reconfiguration of a service provider""s network is becoming increasingly important. Network complexity continues to grow with the addition of network elements, the implementation of high bandwidth connections, such as OC-12, and the multiplexing and demultiplexing of lower bandwidth connections in and out of higher bandwidth connections. The goal of network reconfiguration is to optimize equipment usage and provide the highest possible quality service to the customer while simultaneously reducing cost.
Unfortunately, the current process of reconfiguring a service provider""s network (xe2x80x9cpatch and rollxe2x80x9d) is so slow, costly and has such a negative effect on network performance that the network cannot be optimized. Reconfiguration is so slow that the reconfiguration process can not keep up with equipment and circuit changes, let alone provide for management of traffic and customer demand.
Telecommunication service providers (e.g., MCI Telecommunications Corporation) provide a wide range of services to their customers. These services range from the transport of a standard 64 kbit/s voice channel (i.e., DS0 channel) to the transport of higher rate digital data services (e.g., video). Both voice channels and digital data services are transported over the network via a hierarchy of digital signal transport levels. For example, in a conventional digital signal hierarchy 24 DS0 channels are mapped into a DS1 channel. In turn, 28 DS1 channels are mapped into a DS3 channel.
Routing of these DS1 and DS3 channels within a node of the network is performed by digital cross-connect systems. A node is a point of connection into a network. Digital cross-connect systems typically switch the channels at the DS1 and DS3 signal levels. Transmission of channels between nodes is typically provided via fiber-optic transmission systems. Fiber-optic transmission systems can multiplex a plurality of DS3 channels into a higher rate transmission over a single pair of fibers.
Alternatively, a fiber-optic transmission system can implement the synchronous optical network (SONET) standard. The SONET standard defines a synchronous transport signal (STS) frame structure that includes overhead bytes and a synchronous payload envelope (SPE). One or more channels (e.g., DS1 and DS3 channels) can be mapped into an SPE. For example, a single DS3 channel can be mapped into an STS-1 frame. Alternatively, 28 DS1 channels can be mapped into virtual tributaries (VTs) within the STS-1 frame.
Various STS-1 frames can be concatenated to produce higher rate SONET signals. For example, an STS-12 signal includes 12 STS-1 frames, while an STS-48 signal includes 48 STS-1 frames. Finally, after an STS signal is converted from electrical to optical, it is known as an optical carrier (OC) signal (e.g., OC-12 and OC-48).
The end-to-end path of an in-service channel within a network typically traverses a plurality of nodes. The term xe2x80x9cin-service channelxe2x80x9d is defined as the end to end communication channel that is providing communication service from one customer site or local exchange to another. The process of establishing the in-service channel is called xe2x80x9cprovisioning.xe2x80x9d A new channel that has been established but is not yet carrying communications traffic is called a xe2x80x9cprovisioned channel.xe2x80x9d The in-service channel is carried over transmission facilities that operate at various rates in the digital signal hierarchy. For example, a provisioned DS1 channel may exist as part of a DS3, VT1.5, STS-1, STS-12, OC-12, and OC-48 signal along parts of the end-to-end path. This results due to the switching, multiplexing and demultiplexing functions at each of the nodes.
xe2x80x9cPatch and rollxe2x80x9d is the current process of switching an in-service channel from one node to another, thereby changing the nodes traversed by the in-service channel. Patch and roll first establishes a new communications circuit by adding a new node between two existing nodes on the in-service channel, creating a xe2x80x9cpatch.xe2x80x9d The new communications circuit is tested to obtain a good signal. After a good signal has been obtained, the in-service channel is switched over to the new circuit and the old connection is broken. In order to maintain communications, patch and roll requires that the old in-service channel be switched over one node at a time.
Reconfiguring the network by patch and roll wastes network capacity. Since patch and roll establishes a parallel connection when switching from one node to another, the network must have additional capacity to create the second connection. Designing additional capacity into the network means additional cost for capacity that will not be providing service to the customer.
The current process for reconfiguring the network is too slow. Patch and roll switches one node over at a time, requiring at least two seconds, and often five seconds, to switch each node. With manual coordination, two nodes may be switched over at once. Since a network may contain upwards of 250,000 DS-1 circuits, the time required to reconfigure the network with patch and roll renders network management nearly impossible.
The current process for network reconfiguration makes management of the network very difficult. Maintenance windows are time periods when the network may be reconfigured. In the Digital Data Network (DDN), there are two six-hour maintenance windows per month. Since patch and roll only allows only (at most) eighteen hundred connections to be switched in an hour, only a very small fraction of the connections in the DDN may be switched each month. Because new circuits are added constantly, network traffic, customer needs and bandwidth demands change constantly, the patch and roll method of network management is unacceptable.
The current process for network reconfiguration results in poor network performance. In patch and roll, it takes at least 50 milliseconds to switch each node in the in-service channel over to the provisioned channel. During this time, the in-service channel will be lost. Since patch and roll switches only one node at a time, switching the in-service channel results in numerous communication drop outs. On voice communication channels (switchnet), multiple 50 millisecond drop outs may result in a lost connection or in intermittent distortion. On the Digital Data Network (DDN), however, the 50 millisecond losses will result in dropped computer connections, data errors or software application crashes. Since many nodes may have to be switched, the patch and roll process may result in a total loss of network functionality to the customer, or greatly reduced performance.
In this environment, comprehensive network connection reconfiguration is difficult to accomplish. What is needed is a telecommunication network management system that can switch a large number of nodes on the in-service channel in a short time. This capability will allow network management to free up network capacity, improve customer service and increase the speed of the network.
The present invention satisfies the above mentioned needs by providing a method and system for real time reconfiguration of the network that can switch a large number of network nodes in a very short period of time.
The present invention is a message based system and method for reconfiguring a telecommunications network domain comprising a plurality of network elements. The reconfiguration process begins by identifying a new configuration for the telecommunications network. Next, the process stores the new configuration with the old configuration for the telecommunications network. The system then identifies new connection information associated with the new configuration. The system then downloads the new connection information to the plurality of network elements. After the connection information has been downloaded to the network elements, the connection information is stored with the old connection information at the plurality of network elements. Next, a message is broadcast to the plurality of network elements to activate the new configuration and deactivate the old configuration. The activation of the new connection information stored by the plurality of network elements occurs substantially simultaneously.